Zend certified PHP/Magento developer

Formula for a bit of a non-linear curve

I have data that looks something like this:

enter image description here

I need an Excel formula that given the dollars on the left would produce the quantities on the right.

It’s not a linear regression. The slight curve it has is important.

I just need to generate dummy data along a curve like this. Nothing fancy, and doesn’t have to be exact. Ideally, there would be some kind of log or exponent or inversion that I could put into some other cell to change the curve as needed–but the curving is important.

What is some Excel formula that given the value in column A would produce something close to column B?